In every car manufacturing facility, steel in different parts of the body comes from different production lots, and surface texture varies with the condition of the steel mill rolls which cold roll the steel to its final thickness. Also, surface cleanliness varies with the mill's cleaning procedure, especially the procedures used to control carbon smut.

Often, carbon smut is actually baked onto the steel during the high temperature annealing process which follows rolling. This carbon smut is impossible to remove except by mechanical abrasion. Rust varies with the care taken in handling (1) at the steel mill, (2) during transportation and storage, and (3) during fabrication. Steel stored for a long time with rust inhibiting oil will react to form an incomplete oxide known as oil stain.

The result of all this is that ordinary steel varies widely in the manner in which it accepts coatings. Although some commercial steel provides an excellent surface for coatings, you are just as likely to find steel which gives poor adhesion and poor rust resistance, even with good coatings.

Often the same mill will produce both very good and very poor surface quality, depending upon a number of uncontrolled factors. Nearly all of the above problems can be overcome by using Prep & Ready before you coat with POR-15 Rust Preventive Paint.

1. Removes rust by dissolving it...metal is left clean & ready to paint.
2. Etches metal to provide a better surface profile for painting.
3. Coats the metal with zinc phosphate to inhibit further rusting and promote better paint adhesion.
4. Improves welding conductivity.
5. Removes rust stains from non-metallic surfaces such as porcelain,-ceramic, fiberglass.